Key product standards for Drains and Sewers
WIS
4-35-01	Specification for Thermoplastics Structured Wall Pipes, Joints and Couplers with a Smooth Bore for Gravity Sewers for the Size Range 150-900 Inclusive
BS Standards
4660	Thermoplastics ancillary fittings of nominal sizes 110 and 160 for below ground gravity drainage. BS 4660 1989 was replaced by this standard and  BS EN 1401
4962	Specification for plastic pipes and fittings for use as subsoil field drains
5481	Specification for unplasticized PVC pipes and fittings for gravity sewers Current but superseded by BS EN 1401
7158	Plastics inspection chambers for drains and sewers.
BS EN Standards
1401	Plastics piping systems for non-pressure underground drainage and sewerage - Unplasticized poly(vinyl chloride) (PVC-U)
1852	Plastics piping systems for non-pressure underground drainage and sewerage -Polypropylene
13598	Plastics piping systems for non-pressure underground drainage and sewerage - Ancillary fittings including shallow inspection chambers Unplasticized poly(vinyl chloride)(PVC-U),  polypropylene (PP) and polyethylene (PE).
prENs
12666	Plastics piping systems for non-pressure underground drainage and sewerage - Polyethylene (PE)
13476	Thermoplastics plastics piping systems for non-pressure underground drainage and sewerage - Structured-wall piping systems of PVC-U, PP and PE
14758	Plastics piping systems for non-pressure underground drainage and sewerage - Polypropylene with mineral modifiers (PP-M) - Part 1: Specifications for pipes, fittings and the system.